Mediator join indices

Abstract

A mediator join index (MJI) is proposed to speed up N-way inter-database joins by reducing the amount of data transfer during evaluation. A family of algorithms, the query scrubbing algorithms (QSA), are developed to maintain MJI and to evaluate queries using MJI. QSA algorithms use query scrubbing to cope with update and query anomalies related to materialized views in the mediator context. Compared with existing algorithms, QSA algorithms incur less overhead in handling the anomalies and makes MJI a promising technique for efficient mediator query processing.